class Solution {
    public int minDistance(String word1, String word2) {
        int[][] dp= new int[word1.length()+1][word2.length()+1];
        for(int i=0;i<=word1.length();i++) dp[i][0]=i;
        for(int j=0;j<=word2.length();j++) dp[0][j]=j;
        for(int i=1;i<=word1.length();i++){
            for(int j=1;j<=word2.length();j++){
                if(word1.charAt(i-1)==word2.charAt(j-1)){
                    dp[i][j]=dp[i-1][j-1];
                }else{
                    dp[i][j]=Math.min(dp[i-1][j-1]+2,Math.min(dp[i-1][j]+1,dp[i][j-1]+1));
                }
            }
        }
        return dp[word1.length()][word2.length()];
    }
}